Water-cooled grate



Nov. 11, 1941. w. D. HEDGE l WATERGOOLED GRATE 2 Sheets-Sheet l.

Filed De@ 9. 19:59

Nini :ssl l I www lE-wun N Nov. 11, 1941. w. n. HEDGE WATER-GOOLED GRATE Filed Dec. 9, 1939 `2 Sheebs-Sheekl 2 Patented Nov. 1li, 1941 i UNITED STATES -PiiiTElvT OFFICE, l `,2,262,533 T WATER-cooLnGRA'rE T William D. Hedge, vancouver, Wash. -l Application December 9,1939, Serial No. 3087,439H T n i i solaims. omas-374i The object of this invention "is toprovide a lTwater-cooled furnace grate or grate Setting com- Big. 2- is a transverse section takenon theflnc prising a pluralityof uniform, hollow, cast grate bar elements joined end-to-end in longitudinally eitending courses and withthe courses alternate f ilyrconnected by headers `so as `toprovide a continuous tortuous passageway throughout the en- .Ttire .grate Abar setting. The further object Tof my invention T`is` to provide a grate of this character `in which the` grate elements are secured to each 4other Tby a single bolted connection, the ends of the grate Telement being formed to seat one into .the `other `to provide a watery-tight joint;` `Said parts are constructed and arrangedso that slight angular displacement may be had between eleT- @ments to conform to slight irregularities in the gratebar supports, or otherwise. T

A furthe'robject of my invention is to fastening means which may be engaged and disengaged, oradjusted from the `fire surface of the grate, but which fastening means will lie wholly below the.` re surface so as not readily to be burned out. Tosecure agood seal` it is necessary Tt`oT provide lsome elastic or plastic material for Twhich said `sealing material can be completely provide t jFig. 3 `isan enlargedufragmentaryplan view, with portions shown broken away, of; a Yjoint between two grate bar elements and illustratesA the T sealing and connecting members;

' Fig. V#l is an` end elevation of one of saidgrate Tbanelements taken `on the linel4-f-41in Fig. 3;

, Fig. 5 isa cross-sectional View of one of @said 4grate:y bar elements taken on the line 5-5 `in `Fifa-.7; i l Fig. iisamore or less diagrammatic viewTin-,

` dicating howthe-parts canbe angularly displaced i Fig.` 7I is a slightly sealing the `joints between the grate bar elementf25 "Tand .my invention provides structural features by housed within. and shielded by the grate `bar elements Tand .thus be :subject only tothe heat conducted by .said elements. The grate beingwatercooled is thus maintained toa temperature below the-boiling point of `water and saidsealing material is not subjected to high destructive temperatures, and `can be maintained in proper condition. A further object of myl invention isto arrange i the grate bar elementsl and the water supply if necessary, soi'that theT passageways will not become clogged. i

The details of my invention are hereinafter de- `scribed withreference tothe accompanying draw` ings, in which:

Fig. 1 is a foreshortened plan View of aportion Y of a ygrate bar setting, some grate bar elements being shown Tin section, said figure illustrating the general assembled structure of a water-cooled grate;

lgrate bar elements;

p Fig.` :8 is `ajperspective view of one end 'of without breaking the Water-tight seal `between `adjacent grate bar` elements;

grateybar element showinggthe coupling elements and a recessn for holding acouplingxbolt; Tand "Figr 9` is a foreshortened vertical lview gof a grate with the water conduits shown .in connecitiontherewithl T, T T T :Agrate bar setting or waterooo1ed grate Vfem- ,-bodying my invention comprises a plurality yof 4.grate barelements a. Said elementsfareuniform `and areV joined end-to-end into a plurality Tof longitudinallyextendingcourses. There are as many `grate barelements *in-a course as are necessary to extend `from one endof the furnaceto -the other. ASaideleiments can be of a length which isj-convenientto manufactureandlto install, and

in most casesare approximately two'orthreefeet over all, and thus in a lboiler setting twelve feet longthere would be four or kfive grate bar elements'joined into aflongitudinal course;`

At thefends headers b, which are hollow, join one Tend ofacourse to the `corresponding end of `anadjalnt course, as is indicated in Fig. 1. The

`grate bar elements also are hollow and thus define passageways lengthwise throughy said coursesand with said` headers define a tortuous passageway 'leadngfrom one course to the other. At the endof two coursesyrblanlg headersc are arranged and itis at thesepoints that the water is either admitted or removed. The water is shownasbeing admitted through apipe d in the upper right hand grate bar element in Figs. 1 and 2, and the arrows leading therefrom indicate the paths which the water follows` as it flows through the f grate elements. T ,T

Each grate element ,comprises a plurality of spaced longitudinal fingers e. Said fingers are e `enlarged longitudinalsece. tion, shown gforeshortened,` cfa header and two hollow and thus within each finger there is a branch passageway e. Said passageways e' thus define alternate parallel passageways for the flow of water through each grate bar element. Thus, if one passageway should become clogged or the flow therefrom substantially impeded it would not prevent the flow of water through the other passageways of a grate bar element, but would only affect the particular branch in said grate bar element. At the ends of said branch passageways and within the grate bar element are transverse passageways e2 which are common to, and join all of the passageways e in that particular element.

The hollow bores b of the headers b constitute transverse passageways as has been pointed outy and are of large cross-sectional area. Communi-I eating between the various grate bar units or elements and between the end elements of a course and a header are two apertures f, dened in one element by projecting box-like anges f', and in the other apertures f2 are defined by recess portions f3. Said portions f' and f2 thus constitute male and female joints which seat tightly, one within the other. To insure a water-tight seal I preferably provide heat resisting packing material g which is arranged about the registering apertures f2 between each of the elements. Said packing material is either plastic in nature or is elastic and the pressure produced by the bolted coupling h tends to compress said material y until 'a good seat is had between the flanges f' and the recessed portions f3 into which they seat.

The sides of the box-like flanges f' and the corresponding sides of the recessed portions f3 do not coincide in angle but diverge relatively to a small degree and are preferably rounded in contour so that a limited angular displacement may be produced between coupled elements without tending to'. break the seal between said elements. This is diagrammatically illustrated in Fig. 6.

The bolted couplings are arranged in cup-like recesses i-i' in the adjacent abutting ends of of two grate bar elements. Said recesses are provided with slots i2 and i3 which are of sufiicient width to pass the shank of the bolts but to prevent the passage of the head and nut thereof. Said recesses and slots permit the bolts to be dropped into place and tightened to secure a Water-tight coupling, all of the operations being performed from the plane of the re surface a of the grate, and to be replaced without affecting the remainder of the grate. This permits easy repair and replacement as well as inspection and cleaning of the separate elements.

The bores and passageways of the various elements and headers preferably deiine one continuous passageway throughout a grate. The water flows through a pipe such as b into one end of one of the grate elements and passes back and forth alternately through the adjacent courses and is removed. `The flow of water preferably is constant and is proportioned by manual control so that it is removed before the point of evaporization is reached and the flow is controlled so that said .grates are not cooled unduly, which latter would produce an inefficient re on said grate. A

specific mode of control and the devices therefor .provision is made that the end of any one of said grateelements may receive a tapped coupling for inserting or removing cooling water and the openings which are not utilized are closed by plugs y'.

As is illustrated in Fig. 9, the grate is composed of a plurality of sections lying substantially in a horizontal plane. Thus water admitted through the intake pipe d will tend to ll all of the sections to an equal level. To insure said grate element being constantly filled with water, I provide the water conduit with two upstanding legs, van intake leg k and a discharge leg l. The intake leg has an adjustable valve 7c to regulate the ow of water through said leg lc or to cut off the flow therefrom. In the discharge leg ZI provide a similar valve m. Lying at a point intermediate said legs and immediately inwardly of the discharge leg l is a U-shaped trap n with a discharge pipe o leading therefrom. Said discharge pipe is opened and closed by an adjustable Valve p. Said valve p normally is closed so that water flows from .the leg lc of the pipe d through the sections of the grate elements which form a continuous tortuous passageway therethrough. Leading from a point furthest from the point of ingress of water is a pipe n leading to the trap n and from the latter to the upstanding discharge leg l. It is not necessary that said legs l and lc be of any substantial length, only sufficient to insure the maintenance of a head of water tol prevent the grate elements from being only partially filled with water. For example, it might be necessary only to have the discharge leg l extend upwardly about two or three feet above the grate sov as to maintain a pound or slightly more pressure per square inch of the water in the grate section. If water does not flow sufficiently fast through the grate section, it will tend to produce steam and Ythe steam will escape only if pressure is maintained through the discharge pipe Z to the atmosphere, permitting additional water to flow into said grates.

Frequently, I find that impurities in the water and dissolved substances therein tend to form deposits in the grates. It is difficult to clean said grates although this can be done by removing the headers. I thus provide a discharge pipe o and a manually controlled Valve p therefor, and thus if -the water seemingly is partially clogged by deposits formed within the grates, I open the Valve c and cause the water to flow out through the pipe o. This tends to discharge any foreign solids in the grate, particularly if pressure is increased in the intake pipe leading to said grate. Frequently I have found it desirable to close off both valves lc' and m so that a substantial steam pressure is generated in the grate, and then if the Valve p is suddenly opened, the pressure generated by said steam tends to forcefthe water and the solids therewith outwardly through the discharge pipe o. When this has been accomplished, the valve p can be closed and the valves m and lc opened so that a normal flow of cooling Water will flow through the grate. It is likewise possible to maintain a substantial pressure in the intake leg 1c, close the valve m, and open the valve p retarding the flow through the grate so that steam is generated and with the water contained in said grate will be discharged under pressure from the pipe o.

I claim:

1. A water-cooled furnace grate comprising a plurality of hollow, cast, grate-bar elements joined end-to-end in longitudinally extending courses, each course defining a continuous lineal passagewayfor cooling water,headers disposed at the ends of said courses extending in opposite directions and defining transverse conduits connecting with laterally adjacent courses, thus producing a `plurality of hollow,

grate, each grate-barelement provided witha plurality` of spacedllongitudinally extending fingers,

the upper surfaces of which constitute a grate "fire surface, a couplingelernent projecting from each "grate bar element `joining a complementary coupling element in the `longituc'iinally adjacent grate-bar element, `and a securing member lying adjacent said coupling element l and positioned to engage Aand hold two longitudinally` adjacent `grate-bar elements together and the complementary coupling elements seated one in the other.

2. A `water-cooled furnace grate comprising a pluralityof` hollow,cast, grate-bar elements joined end-to-end in longitudinally extending courses, each course defining a continuous lineal passagenly to `pass the shank ofthe `securing member, ibut `to retain rthe headsthereof. l i

5. A Water-cooled` furnace grate comprising a lplurality of hollow, cast, grate-bar elements of uniform characteristics joined end-to-end in 1ongitudinally extending courses each course defining a continuous 'lineal passageway forcooling water,*headers disposed at the ends of "said `way for cooling water, yheaders disposed at the ends of said courses extending in opposite directions and defining transverse conduits connecting with laterally adjacent courses, thus producing a continuous tortuous passageway throughout the grate, each grate-bar element provided with a plurality of spaced longitudinally extending fingers, the upper surfaces of whichfconstitute a grate fire surface, a coupling element projecting from each end of each grate-bar element and from one face of each header joining a complementary coupling element in the longitudinally adjacent grate-bar element or header,

` and a threaded securing" member positioned to engage and hold two longitudinally adjacent grate-bar elements or element and header, respectively, together, said securing member being proportioned and arranged to accommodate limited angular displacement of the grate elements gers, the upper surfaces `of which constitute a grate fire surface, and a securing memberpositioned to engage and hold two longitudinally adjacent grate elements together, said securing member lying in cup-like apertures arranged at the abutting ends of two adjacent grate elements and opening to the upper surface thereof.

4; A water-cooled furnace grate comprising a cast, grate-bar elements joined end-to-end in longitudinally extending courses, each course defining a continuous lineal passageway for cooling water, headers disposed at the ends of said courses extending in opposite directions and defining transverse conduits connecting with laterally adjacent courses, thus producing a continuous tortuous passageway throughout the grate, each grate-bar element provided with a plurality of spaced longitudinally extending fingers, the upper surfaces of which constitute a grate fire surface, and a two-headed securing member positioned to engage and hold two longitudinally adjacent grate elements together, said securing member lying in cup-like apertures arranged at the abutting ends of two adjacent grate elements and opening to the upper surface thereof,` said apertures being slotted longitudinaland headers without affectingthe seal between courses extending in opposite directions and defning transverse conduits connecting withflaterally adjacent courses, thus producing a Ycontinuous tortuous passageway throughout .the grate, each grate `bar element provided with-a plurality of spaced longitudinally extending'fingers, the upper surfaces of which constitute a grate fire surface, said grate-bar. elements being hollow and defining longitudinallyextending parallel conduits for cooling water, and transverse passageways at, and within the confines of, the ends of Veach of said elements connecting said parallel conduits, and coupling elements projecting from each grate element and from one face of each header joining complementary elements in longitudinally adjacent grate elements and headers, respectively.

6. A water-cooled furnace grate comprising a plurality 0f hollow, cast, grate-bar elements joined end-to-end in longitudinally extending courses each course defining a continuous lineal passageway for cooling water, headers disposed at the ends of said courses extending in opposite directions and defining transverse conduits connecting with laterally adjacent courses thus producing a continuous tortuous passageway throughout the grate, each grate-bar element provided with a plurality of spaced longitudinally extending fin- "gers, the upper surfaces of whichY constitute a grate fire surface, said grate-bar elements being hollow and defining longitudinally extending parallel conduits for cooling water, a pair of coupling elements projecting from each grate-bar element, joining complementary coupling elei ments in the longitudinally adjacent grate-bar element, and a securing member lying intermediate said coupling elements and positioned to engage and hold two longitudinally adjacent grateelements together, the complementary coupling elements seated one in the other.

7. A water-cooled furnace grate comprising a Vplurality of hollow-cast, grate-bar elements joined end-to-end in longitudinally extending courses each course defining a continuous lineal passageway for cooling water, headers disposed at the ends of said courses extending in opposite directions and defining transverse conduits'connecting with laterally adjacent courses, thus producing a continuous vtortuous passageway throughout the grate, each grate-bar element provided `with a plurality of spaced longitudinally extending iingers, the upper surfaces of which constitute a grate fire surface, said grate-bar elements being hollow and defining longitudinally extendplurality of hollow, cast, grate-bar elements of uniform characteristics joined end-to-end in longitudinally extending courses each course defining a continuous lineal passageway for cooling water, headers disposed at the ends of said courses extending in opposite directions and dening transverse conduits connecting with laterally adjacent courses, thus producing a continuous tortuous passageway throughout the grate, each grate bar element provided with a plurality of spaced longitudinally extending iingers, the upper surfaces of which constitute a grate fire surface, said grate-bar elements being hollow and dening longitudinally extending parallel conduits for cooling Water, and transverse passageWays at,

.and Within the connes of, the ends of each of said elements connecting said parallel conduits, and coupling elements projecting from each grate element and from one face of each header joining complementary elements in longitudinally adjacent grate elements and headers, respectively, and a Water supply means and Water discharge means for said grate, each of said latter tWo means including a, conduit having an upstanding leg, each of said legs extending to a point substantially above the horizontal plane of the longitudinal courses of the grate.

WILLIAM D. HEDGE. 

